Abstract:

An apparatus for cooling a heat-generating component is disclosed. The
apparatus includes a cooling chamber containing a liquid metal. The
cooling chamber has a heat-conducting wall thermally coupled to the
heat-generating component. A plurality of extendable tubes making up an
array of cooling pin fins is attached to the cooling chamber. Each of the
extendable tubes has a port end that opens into the cooling chamber and a
sealed end that projects away from the cooling chamber. Moreover, each of
the extendable tubes has an extended position when filled with liquid
metal from the cooling chamber and a retracted position when emptied of
the liquid metal. A pump system is included for urging the liquid metal
from the cooling chamber into the plurality of extendable tubes.

Claims:

1. An apparatus, comprising:a heat-generating component;a heat sink with a
cooling chamber containing a cooling fluid, said cooling chamber having a
heat conducting wall thermally coupled to said heat-generating component;
anda plurality of extendable tubes attached to said heat sink, each of
said tubes having a port end that opens into said cooling chamber and a
sealed end that projects away from said cooling chamber, each of said
extendable tubes having an extended position when filled with said
cooling fluid and a retracted position when emptied of said cooling
fluid.

2. The apparatus of claim 1, further including a pump system for urging
said cooling fluid from said cooling chamber into said plurality of
extendable tubes.

3. The apparatus of claim 2, further including an electronic pump control
system interfaced with at least one temperature sensor that monitors the
temperature of said heat-generating component.

4. The apparatus of claim 3, wherein said electronic pump control system
includes a micro-controller for activating the pump system to urge
cooling fluid into said plurality of extendable tubes to force them into
their extended position when said at least one temperature sensor reports
at least one temperature measurement above a predetermined threshold.

5. The apparatus of claim 4, wherein said micro-controller is embedded in
said heat sink.

6. The apparatus of claim 3, wherein said at least one temperature sensor
is embedded in said heat conducting wall thermally coupled to said
heat-generating component.

7. The apparatus of claim 1, wherein said cooling fluid is a liquid metal.

8. The apparatus of claim 1, further including at least one baffle
dividing said cooling chamber into compartments such that said cooling
fluid may be selectively directed into predetermined groups of said
plurality of extendable tubes.

9. The apparatus of claim 1, wherein each of said extendable tubes
comprise a bellows having a longitudinal axis along which said bellows
extends when filled with said cooling fluid and retracts when emptied of
said cooling fluid.

10. The apparatus of claim 9, wherein said bellows is cylindrical.

11. The apparatus of claim 1, wherein said extendable tubes include a
section adapted to carry radial cooling fins.

12. The apparatus of claim 2, wherein said pump system includes at least
one solenoid pump comprising a coil winding over a tubular liner that
defines a solenoid core volume, and a core plunger made of magnetic
material, said core plunger having a coil winding energized position
substantially inside said solenoid core, thereby taking up said solenoid
core volume and a coil winding de-energized position substantially
outside said solenoid core volume.

13. The apparatus of claim 12, wherein said tubular liner is made of a
material that is resistant to damage from both the temperature and the
composition of said cooling fluid.

14. The apparatus of claim 12, wherein said at least one solenoid pump
core volume is dimensioned to contain a volume of cooling fluid equal to
the amount of cooling fluid needed to maintain said extendable tubes into
their extended position when said coil winding is energized and said
plunger takes up said solenoid core volume.

15. An apparatus, comprising:a heat-generating component;a heat sink with
a cooling chamber containing a liquid metal, said cooling chamber having
a heat conducting wall thermally coupled to said heat-generating
component;a plurality of extendable tubes attached to said heat sink,
each of said tubes having a port end that opens into said cooling chamber
and a sealed end that projects away from said cooling chamber, each of
said extendable tubes having an extended position when filled with liquid
metal from said cooling chamber and a retracted position when emptied of
said liquid metal; anda pump system for urging said liquid metal from
said cooling chamber into said plurality of extendable tubes.

16. The apparatus of claim 15, further including an electronic pump
control system interfaced with at least one temperature sensor embedded
in said heat conducting wall thermally coupled to said heat-generating
component.

17. The apparatus of claim 16, wherein said electronic pump control system
includes a micro-controller embedded in said heat sink for activating the
pump system to urge said liquid metal into said plurality of extendable
tubes to force them into their extended position when said at least one
temperature sensor reports at least one temperature measurement above a
predetermined threshold.

18. The apparatus of claim 15, further including at least one baffle
dividing said cooling chamber into compartments such that said liquid
metal may be selectively directed into predetermined groups of said
plurality of extendable tubes.

19. The apparatus of claim 15, wherein each of said extendable tubes
comprise a bellows having a longitudinal axis along which said bellows
extends when filled with said liquid metal and retracts when emptied of
said liquid metal.

20. The apparatus of claim 15, wherein said extendable tubes include a
section adapted to carry radial cooling fins.

21. The apparatus of claim 16, wherein said pump system includes at least
one solenoid pump comprising a coil winding over a tubular liner that
defines a solenoid core volume, and a core plunger made of magnetic
material, said core plunger having a coil winding energized position
substantially inside said solenoid core, thereby taking up said solenoid
core volume and a coil winding de-energized position substantially
outside said solenoid core volume.

22. The apparatus of claim 21, wherein said tubular liner is made of a
material that is resistant to damage from both temperature and the
composition of said liquid metal.

23. The apparatus of claim 21, wherein said at least one solenoid pump
core volume is dimensioned to contain a volume of liquid metal equal to
the amount of liquid metal needed to maintain said extendable tubes into
their extended position when said coil winding is energized and said
plunger takes up said solenoid core volume.

24. A method of cooling a heat-generating component, said method
comprising steps of:providing a heat sink having a cooling chamber
containing a cooling fluid, said cooling chamber having a heat conducting
wall thermally coupled to said heat-generating component;providing a
plurality of extendable tubes attached to said heat sink, each of said
tubes having a port end that opens into said cooling chamber and a sealed
end that projects away from said cooling chamber, each of said extendable
tubes having an extended position when filled with said cooling fluid and
a retracted position when emptied of said cooling fluid;providing a pump
system for urging said cooling fluid from said cooling chamber into said
plurality of extendable tubes, said pump system including an electronic
pump control system interfaced with at least one temperature sensor that
monitors the temperature of said heat-generating component; andpumping
said cooling fluid from said cooling chamber into said extendable tubes
when said at least one temperature sensor reports a temperature that is
greater than a predetermined temperature threshold.

25. An apparatus, comprising:a heat-generating component;a heat sink with
a cooling chamber containing a liquid metal, said cooling chamber having
a heat conducting wall thermally coupled to said heat-generating
component;a plurality of extendable tubes attached to said heat sink,
each of said tubes having a port end that opens into said cooling chamber
and a sealed end that projects away from said cooling chamber, each of
said extendable tubes having an extended position when filled with liquid
metal from said cooling chamber and a retracted position when emptied of
said liquid metal;a pump system for urging said liquid metal from said
cooling chamber into said plurality of extendable tubes; andan electronic
pump control system that includes a micro-controller in communication
with at least one temperature sensor for activating said pump system to
urge said liquid metal into said plurality of extendable tubes to force
them into their extended position when said at least one temperature
sensor reports at least one temperature measurement above a predetermined
threshold.

Description:

FIELD OF THE INVENTION

[0001]The present invention relates to cooling heat-producing devices. In
particular, the present invention pertains to electronic systems that use
pin-fin type heat sinks to remove heat from electronic devices such as
high-speed microprocessors.

BACKGROUND OF THE INVENTION

[0002]Efficient cooling of integrated circuits (IC) devices is essential
to prevent failure due to excessive heating. Cooling demands continue to
grow as the number of complimentary metal oxide semiconductor (CMOS)
devices per chip and clock speeds increases, such efficient cooling has
become an even more prominent concern. For example, while the current
generation of microprocessors generates heat on the order of 100 W/cm2,
the next generation of computer microprocessors is expected to reach heat
generation levels of 200 W/cm2 or more.

[0003]IC chips are conventionally cooled by a heat exchange mechanism, or
heat sink, having a thermally conductive plate coupled to the chip. The
plate typically has a plurality of raised fins or pin fins extending from
one of its surfaces. The pin fins increase the surface area over which
air may flow, thereby increasing the rate of heat transfer from the heat
sink to the surrounding air.

[0004]Such air-cooled methods have generally proven to be reliable in
facilitating heat transfer for current chips. However, it is generally
concluded that current methods of forced air-cooling have reached their
limits of performance. Moreover, conventional heat sinks are currently
designed to have set dimensions and are not adaptable to differing
environmental conditions. As such, the trend towards smaller, more
powerful chips that generate even greater amounts of heat makes continued
reliance on conventional air cooled methods inadequate.

[0005]Thus, there is a need for a heat exchange apparatus that is capable
of providing a heat sink that is dimensionally adaptable to differing
environmental conditions.

SUMMARY OF THE INVENTION

[0006]The present invention provides an improved computer implemented
apparatus, and method for cooling a heat-generating component in a
changing environment. Embodiments of the present invention improve
cooling efficiency by providing an apparatus comprising a heat-generating
component, a heat sink with a cooling chamber containing a cooling fluid,
the cooling chamber having a heat conducting wall thermally coupled to
the heat-generating component, and a plurality of extendable tubes
attached to the heat sink. Each tube may have a port end that opens into
the cooling chamber and a sealed end that projects away from the cooling
chamber. The extendable tubes may have an extended position when filled
with the cooling fluid and a retracted position when emptied of the
cooling fluid. The cooling fluid may be liquid metal.

[0007]Aspects of the invention may further include a pump system for
urging the cooling fluid from the cooling chamber into the plurality of
extendable tubes. The electronic pump control system may be interfaced
with at least one temperature sensor that monitors the temperature of the
heat-generating component. At least one temperature sensor may be
embedded in the heat conducting wall thermally coupled to the
heat-generating component. The electronic pump control system may also
include a micro-controller for activating the pump system to urge cooling
fluid into the plurality of extendable tubes to force them into their
extended position when the temperature sensor reports a temperature
measurement above a predetermined threshold. The micro-controller may be
embedded in the heat sink.

[0008]Embodiments of the invention may include at least one baffle
dividing the cooling chamber into compartments. The cooling fluid may be
selectively directed into predetermined groups of the plurality of
extendable tubes. Each of the extendable tubes may include a section
adapted to carry radial cooling fins. Each tube may comprise a bellows
having a longitudinal axis along which the bellows extends when filled
with the cooling fluid and retracts when emptied of the cooling fluid.
The bellows may be cylindrical.

[0009]The pump system of an embodiment may include at least one solenoid
pump comprising a coil winding over a tubular liner that defines a
solenoid core volume, and a core plunger made of magnetic material. The
core plunger may have a coil winding energized position substantially
inside the solenoid core, thereby taking up the solenoid core volume. The
core plunger may also have a coil winding de-energized position
substantially outside the solenoid core volume. The tubular liner may be
made of a material that is resistant to damage from both the temperature
and the composition of the cooling fluid. The solenoid pump core volume
may be dimensioned to include a volume of cooling fluid equal to the
amount of cooling fluid needed to maintain the extendable tubes into
their extended position when the coil winding is energized and the
plunger takes up the solenoid core volume.

[0010]Another embodiment of the invention may comprise a heat-generating
component, a heat sink with a cooling chamber containing a liquid metal.
The cooling chamber may have a heat conducting wall thermally coupled to
the heat-generating component, and a plurality of extendable tubes
attached to the heat sink. Each of the tubes may have a port end that
opens into the cooling chamber and a sealed end that projects away from
the cooling chamber. Each of the extendable tubes may also have an
extended position when filled with liquid metal from the cooling chamber
and a retracted position when emptied of the liquid metal, and a pump
system for urging the liquid metal from the cooling chamber into the
plurality of extendable tubes.

[0011]The apparatus may further include an electronic pump control system
interfaced with at least one temperature sensor embedded in the heat
conducting wall thermally coupled to the heat-generating component. The
electronic pump control system may also include a micro-controller
embedded in the heat sink for activating the pump system to urge the
liquid metal into the plurality of extendable tubes to force them into
their extended position when the at least one temperature sensor reports
at least one temperature measurement above a predetermined threshold.

[0012]Embodiments may further include at least one baffle dividing the
cooling chamber into compartments such that the liquid metal may be
selectively directed into predetermined groups of the plurality of
extendable tubes. The extendable tubes may comprise a bellows having a
longitudinal axis along which the bellows extends when filled with the
liquid metal and retracts when emptied of the liquid metal. The
extendable tubes may include a section adapted to carry radial cooling
fins.

[0013]Aspects of the pump system may also include at least one solenoid
pump comprising a coil winding over a tubular liner that defines a
solenoid core volume, and a core plunger made of magnetic material. The
core plunger may have a coil winding energized position substantially
inside the solenoid core, thereby taking up the solenoid core volume and
a coil winding de-energized position substantially outside the solenoid
core volume. The tubular liner may be made of a material that is
resistant to damage from both temperature and the composition of the
liquid metal. The solenoid pump core volume may be dimensioned to contain
a volume of liquid metal equal to the amount of liquid metal needed to
maintain the extendable tubes into their extended position when the coil
winding is energized and the plunger takes up the solenoid core volume.

[0014]Embodiments of the invention also include a method of cooling a
heat-generating component, the method comprising steps of providing a
heat sink having a cooling chamber containing a cooling fluid. The
cooling chamber may have a heat conducting wall thermally coupled to the
heat-generating component, providing a plurality of extendable tubes
attached to the heat sink. Each of the tubes may have a port end that
opens into the cooling chamber and a sealed end that projects away from
the cooling chamber. Each of the extendable tubes may also have an
extended position when filled with the cooling fluid and a retracted
position when emptied of the cooling fluid, providing a pump system for
urging the cooling fluid from the cooling chamber into the plurality of
extendable tubes. The pump system may include an electronic pump control
system interfaced with at least one temperature sensor that monitors the
temperature of the heat-generating component, and pumping the cooling
fluid from the cooling chamber into the extendable tubes when the at
least one temperature sensor reports a temperature that is greater than a
predetermined temperature threshold.

[0015]Another aspect of the invention may comprise a heat-generating
component, a heat sink with a cooling chamber containing a liquid metal.
The cooling chamber may have a heat conducting wall thermally coupled to
the heat-generating component, and a plurality of extendable tubes
attached to the heat sink. Each of the tubes may have a port end that
opens into the cooling chamber and a sealed end that projects away from
the cooling chamber. Each of the extendable tubes may also have an
extended position when filled with liquid metal from the cooling chamber
and a retracted position when emptied of the liquid metal, a pump system
for urging the liquid metal from said cooling chamber into the plurality
of extendable tubes, and an electronic pump control system that includes
a micro-controller in communication with at least one temperature sensor
for activating the pump system. The pump system may urge the liquid metal
into the plurality of extendable tubes to force them into their extended
position when the at least one temperature sensor reports at least one
temperature measurement above a predetermined threshold.

[0016]These and other advantages and features that characterize the
invention are set forth in the claims annexed hereto and forming a
further part hereof. However, for a better understanding of the
invention, and of the advantages and objectives attained through its use,
reference should be made to the Drawings and to the accompanying
descriptive matter in which there are described exemplary embodiments of
the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1 is a side cross-sectional view of the heat sink apparatus
according to one embodiment of the invention.

[0018]FIG. 2 is a perspective view of an extendable tube with a section
adapted to carry a micro-fin radiator.

[0019]FIG. 3 is a perspective view of a solenoid pump winding on a tubular
core that has an open solenoid core volume.

[0020]FIG. 4 is a perspective view of the solenoid pump with a core
plunger in the solenoid de-energized position.

[0021]FIG. 5 is a perspective view of the solenoid pump with the core
plunger in the solenoid energized position.

[0022]FIG. 6 is an upside down perspective view of a baffle structure with
attached solenoid pumps according to one embodiment of the invention.

[0023]FIG. 7 shows an electronic pump control system in communication with
a solenoid pump.

[0024]FIG. 8 shows a flowchart having method steps used to realize and
operate an embodiment of the present invention.

[0025]FIG. 9 shows an external perspective view of an assembled embodiment
of the present invention.

DETAILED DESCRIPTION

[0026]Embodiments consistent with the present invention include a method
and apparatus for cooling a semiconductor heat source. Generally, aspects
of the invention include a heat sink having an array of extendable pin
fins that can adapt to changing environmental conditions. The function is
that of an inter-leaving heat sink filled with a liquid metal.

[0027]Specifically, the heat sink's pin fins may extend taller or retract
shorter based upon an environmental feedback from temperature sensors,
such as thermocouples that sense the temperature of the semiconductor
device or other heat-generating component being cooled. Associated
circuitry such as digital logic, and a micro-controller programmed with
software and/or firmware for controlling the pin fin extension and
retraction process is embedded in the heat sink.

[0028]The heat sink includes a cooling chamber that includes a cooling
fluid such as a liquid metal. A heat conducting wall of the cooling
chamber may be thermally coupled to the cooling chamber. A plurality of
extendable tubes makes up the array of extendable pin fins. Each of the
extendable tubes has a port end that opens into the cooling chamber and a
sealed end that projects away from the cooling chamber. Each of the
extendable tubes (i.e., pin fins) may have an extended position when
filled with the cooling fluid and a retracted position when emptied of
the cooling fluid. A pump system for urging the cooling fluid from the
cooling chamber and into the plurality of extendable tubes may also be
included. Moreover, excellent heat conduction is realizable if the
cooling fluid is a liquid metal, as is called for in one embodiment of
the invention. Any number of heat sinks can be controlled individually or
controlled at a system level to include feedback for air moving devices
such as fans, and other environmental conditions inside and/or outside a
server/computer.

[0029]While embodiments of the invention are illustrated with respect to a
semiconductor microprocessor as a heat-generating component, it should be
understood that embodiments of the invention may be used to cool other
types of semiconductor chips and electronic or electrical devices, as
well as any other heat-generating component or device. Similarly, an
embodiment of the invention is illustrated having a cooling fluid and
fluid pumps, but the invention may also be practiced with other well
known cooling devices such as a fan to move air as an additional cooling
fluid over the heat sink.

[0030]FIG. 1 shows a cross-sectional view of the apparatus consistent with
embodiments of the present invention. The apparatus 100 generally
includes a heat-generating component 102 and a heat sink 104 with a
cooling chamber 106 having a heat conducting wall 108 thermally coupled
to heat-generating component 102. Cooling chamber 106 is for containing a
cooling fluid 110 such as a liquid metal. Liquid metals have a high
thermal conductivity that allows for efficient thermal coupling to
heat-generating component 102. For example, cooling fluid 110 may
comprise at least one of: gallium, indium, tin, bismuth, sodium, and
potassium. The cooling fluid 110 may be in a liquid state over the
desired range of operating temperatures of apparatus 100. Cooling fluid
110 may also comprise a gallium tin alloy, (e.g., a gallium indium tin
eutectic).

[0031]The heat conduction wall 108 may be coupled to the heat-generating
component 102 by adhesive or by mechanical joining such as by screwing,
bolting, clamping, and the like, and in a manner suitable to prevent
leakage of the cooling fluid 110 from the cooling chamber 106. In one
embodiment, the heat sink 104 and heat-conducting wall 108 may be made of
copper or aluminum.

[0032]Optionally, a coating (not shown) may be disposed on the inner
surfaces of cooling chamber 106. The coating may improve compatibility
between the cooling fluid 110 and the materials comprising the inner
surfaces of cooling chamber 106. The coating may be selected to enhance
the adhesion of the heat conducting wall 108 to the heat-generating
component 102. The coating may also be selected to act as an oxidation
prevention outer layer, or to enhance the wettability of the cooling
fluid 110 with respect to the cooling chamber's inner surfaces. It is
contemplated that multiple coatings may be provided. For example, a first
coating may protect the inner surfaces of cooling chamber 106 from the
cooling fluid 110, and a second coating may enhance the wettability of
the cooling fluid over the inner surfaces of the cooling chamber 106.

[0033]The coatings may be applied by any conventional means, such as by
evaporation, sputtering, plating, chemical vapor deposition, and the
like. The thickness of the coating or coatings is chosen for robustness
in the presence of the cooling fluid 110, and generally will depend upon
the material comprising the coating, the method of application, and the
coverage required to achieve the intended purpose of the coating. In one
embodiment where the cooling fluid 110 comprises a liquid metal, the
coating may comprise of chromium, gold, molybdenum, nickel, platinum,
tantalum, titanium, and tungsten. In another embodiment, a chromium
coating is disposed on the cooling chamber 106 and has a coating of
either gold or platinum disposed on top of the chromium. The chromium
coating may be formed to a thickness of about 2500 angstroms. The gold or
platinum coating may be formed to a thickness of about 300 angstroms.
Optionally, a coating of titanium 500 angstroms thick, for example, may
be formed on the inner surfaces of cooling chamber 106 in place of or on
top of the layer of chromium.

[0034]As shown in FIGS. 1, 6 and 9, a plurality of extendable tubes 112
making up a pin fin array is attached to heat sink 104. Each of
extendable tubes 112 have a port end 114 that opens into cooling chamber
106, and a sealed end 116 that projects away from cooling chamber 106.
Moreover, as shown in FIG. 1 each of extendable tubes 112 have an
extended position 120 when filled with cooling fluid 110 and a retracted
position 122 when emptied of cooling fluid 110. Also, as depicted in
FIGS. 1 and 6, cooling chamber 106, may further include at least one
baffle 118 that divides cooling chamber 106 into compartments 107A and
107B such that cooling fluid 110 may be selectively directed into
predetermined groups of the plurality of extendable tubes 112.

[0035]As best seen in FIGS. 1 and 2, each of the extendable tubes 112 may
comprise a bellows 200. Each bellows 200 may extend along a longitudinal
axis 202 when filled with cooling fluid 110. Each bellows 200 may retract
when emptied of cooling fluid 110. The bellows 200 may be cylindrical,
but it could also be other volume containing shapes depending on
practicality and other engineering factors such as thermal radiation
ability, etc. Moreover, the extendable tubes 112 may also include a
section adapted to carry radial cooling fins 204. As shown in FIG. 2, the
sealed ends 116 of the extendable tubes 112 may be adapted to carry
radial cooling fins 204, which may be micro fins.

[0036]Turning now to FIGS. 3-5, a pump system 300 may be included for
urging cooling fluid 110 from cooling chamber 106 and into the plurality
of extendable tubes 112. In one embodiment, the pump system 300 includes
at least one solenoid pump 302 having a coil winding 304 over a tubular
liner 306 that defines a solenoid core volume 308. The tubular liner is
made of a material such as ceramic or plastic that is resistant to damage
from both the temperature and chemical composition of cooling fluid 110.

[0037]As shown in FIG. 4, solenoid pump 302 also includes a core plunger
310 made of a magnetic material such as steel. Core plunger 310 is sized
such that it substantially takes up the solenoid core volume 308 when the
core plunger 310 is pulled inside the solenoid core volume 308 when coil
winding 304 is energized with electrical current that generates a
magnetic field.

[0038]FIG. 5 shows core plunger 310 in a coil winding energized position
312 that is substantially inside the solenoid core, thereby taking up the
solenoid core volume, and a coil winding de-energized position 314
substantially outside the solenoid core volume. Moreover, the solenoid
core volume 308 may be dimensioned to include a volume of cooling fluid
110 that is equal to the amount of cooling fluid 110 needed to maintain
the extendable tubes into their extended position when the coil winding
304 is energized, which results in the core plunger 310 substantially
taking up the solenoid core volume 308. Preferably, the solenoid tubular
liner 306 includes a flexible containment seal 316 for preventing leakage
of the cooling fluid 110 during an inward core stroke of the core plunger
310.

[0039]FIG. 7 depicts an electronic pump control system 400 that may be
interfaced with at least one temperature sensor 402 that monitors the
temperature of heat-generating component 102. At least one temperature
sensor 402 may be a thermocouple type temperature sensor embedded in heat
sink 104 and preferably embedded into the heat conducting wall 108
thermally coupled to the heat-generating component 102. Electronic pump
control system 400 may include a micro-controller 404 programmed with
software and/or firmware for activating pump system 300 to urge cooling
fluid into the plurality of extendable tubes to force them into their
extended position when the at least one temperature sensor reports at
least one temperature above a predetermined threshold.

[0040]At least one solenoid pump 302 may be associated with each of the
compartments 107A and 107B shown in FIG. 1. In this way, the solenoid
pump 302 in fluidic communication with one of compartments 107A or 107B
may be individually energized to extend one of the predetermined groups
of extendable tubes 112 into their extended position 120 while leaving
other predetermined groups of extendable tubes 112 in their retracted
position 122.

[0041]Turning now to FIG. 8, embodiments consistent with the present
invention also include a method 500 of cooling the heat-generating
component 102. Step 502 provides heat sink 104 having the cooling chamber
106 containing the cooling fluid 110, wherein the heat conducting wall
108 may be thermally coupled to the heat-generating component 102.

[0042]At step 504, the pump system 300 provides a plurality of extendable
tubes attached to the heat sink 104. Each of the extendable tubes 112 may
include a port end 114 that opens into the cooling chamber 106 and a
sealed end 116 that projects away from the cooling chamber 106. Each of
the extendable tubes 112 has an extended position 120 when filled with
the cooling fluid 110 and a retracted position 122 when emptied of the
cooling fluid 110.

[0043]Another step 506 provides the pump system 300 for urging the cooling
fluid 110 from the cooling chamber 106 into the plurality of extendable
tubes 112. The pump system 300 includes an electronic pump control system
400 that is interfaced with a temperature sensor 402 that monitors at
step 508 the temperature of the heat-generating component 102.

[0044]In operation, the method includes a step 514 of pumping the cooling
fluid 110 from the cooling chamber 106 into the extendable tubes 112 when
the temperature sensor 402 reports a temperature that is greater than a
predetermined high temperature threshold, as determined at block 510. In
contrast, cooling fluid 110 is allowed to flow out of the extendable
tubes 112 at step 516 when the temperature sensor 402 reports at block
512 a temperature that is less than a predetermined low temperature
threshold.

[0045]As shown assembled in FIG. 9 and discussed above, a heat sink method
and apparatus is disclosed that facilitates improved heat transfer away
from a heat-generating component, such as an IC chip, thereby allowing
the IC chip to operate more reliably and efficiently than IC chips cooled
by conventional methods. It should be noted that the orientation of the
apparatus in the drawings and in any positional terms such as above and
below are illustrative terms to show the relative configuration of
components in the apparatus and are not limiting of scope. For example,
the apparatus could be inverted or rotated at any angle with respect to
the embodiments depicted herein.

[0046]That is, while the present invention has been illustrated by a
description of various embodiments and while these embodiments have been
described in considerable detail, it is not the intention of the
Applicants to restrict, or, in any way limit the scope of the appended
claims to such detail. The invention in its broader aspects is therefore
not limited to the specific details, representative apparatus and method,
and illustrative example shown and described. Accordingly, departures may
be made from such details without departing from the spirit or scope of
Applicants' general inventive concept.